STUDY ON LIMIT OF FLOOD MITIGATION EFFECT OF PADDY FIELD DAM

Abstract

 We carried out flood simulations using a numerical model, and verified the adaptive limit rainfall of the flood damage mitigation effect of the Paddy Field Dam (PFD) in the Somaigi River basin in Tochigi Prefecture. As a result, it was clarified that the maximum effect of the PFD is demonstrated by the rainfall with 120-year (268 mm/day) return periods in this basin. It was also confirmed that although the amount of inundation could be reduced up to about 700 mm/day of rainfall, it was confirmed that the effect of PFD decreased as the amount of rainfall increased, since the number of paddy fields flooding above the height of levee on paddy filed increased.